An optical wavelenth selective filter on an optical waveguide and a method of making the same is provided. The filter is able to transmit a first predetermined band of wavelengths and to reflect a second predetermined band. The filter further includes a plurality of transmissive couples and reflective couples in series, with each of the couples including a first zone of high refractive index and a second zone of low refractive index adjacent to each other so as to form a structure with a high gap modulated refractive index.